The invention is particularly applicable to cupping, drawing and ironing operations in the making of metal cans, especially aluminum cans. In the manufacture of such cans, the initial operation is usually referred to as a cupping operation and involves forming the metal into a cup at pressures of 2,000-2,500 pounds per square inch gauge (psig). The metal is then redrawn to elongate the sides and afterwards it is ironed at higher pressures around 5,000 psig to increase the length of the sides and diminish the thickness.
These operations require lubrication of the metal and various types of lubricants containing mineral oil, together with fatty acids and aliphatic carboxylic acid ester emulsifying agents have heretofore been employed. Knepp, U.S. Pat. No. 3,923,671, discloses examples of such lubricants.
Davis, U.S. Pat. No. 3,374,171, discloses a cutting fluid comprising an alkanolamine, a polyoxyalkylene glycol and a saturated organic acid containing from 6 to 9 carbon atoms. According to the disclosure in this patent, however, the use of higher molecular weight saturated organic acids is to be avoided because of clogging of filters, poor rust protection and reduced tool life in areas where hard water is encountered.